[Elecraft] KPA500 IMD tests with K3 driving it

[Dave Johnson]

I found time to run a few 2 tone IMD tests with my K3 and KPA500
combination today, these were on 80m using a 50 Ohm Cantenna load with the
spectrum measurements taken with a Microtelecom Perseus SDR. The SDR
receiver was coupled via a loop of wire around the coax to the Cantenna.
The two tones used in the test are from the internal 2 tone generator in
the K3.

First the K3 running at 20 Watts, the approximate power level used to drive
the KPA500 to 400 Watts output:
http://www.astromag.co.uk/images/K3_2tone_20W.jpg

Secondly the K3/KPA500 running 400 Watts:
http://www.astromag.co.uk/images/KPA500_2tone_400W.jpg

Thirdly, the K3 running 100 Watts output with a spoken "four" into the
microphone:
http://www.astromag.co.uk/images/K3_voice_100W.jpg

Finally, the K3/KPA500 running 400 Watts with a "four" as above:
http://www.astromag.co.uk/images/KPA500_voice_400W.jpg

Anyone got similar plots they would like to share?

73 Dave